trackerclient.cpp Example File

torrent/trackerclient.cpp

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  #include "bencodeparser.h"
  #include "connectionmanager.h"
  #include "torrentclient.h"
  #include "torrentserver.h"
  #include "trackerclient.h"

  #include <QtCore>
  #include <QNetworkRequest>

  TrackerClient::TrackerClient(TorrentClient *downloader, QObject *parent)
      : QObject(parent), torrentDownloader(downloader)
  {
      length = 0;
      requestInterval = 5 * 60;
      requestIntervalTimer = -1;
      firstTrackerRequest = true;
      lastTrackerRequest = false;
      firstSeeding = true;

      connect(&http, SIGNAL(finished(QNetworkReply*)), this, SLOT(httpRequestDone(QNetworkReply*)));
  }

  void TrackerClient::start(const MetaInfo &info)
  {
      metaInfo = info;
      QTimer::singleShot(0, this, SLOT(fetchPeerList()));

      if (metaInfo.fileForm() == MetaInfo::SingleFileForm) {
          length = metaInfo.singleFile().length;
      } else {
          QList<MetaInfoMultiFile> files = metaInfo.multiFiles();
          for (int i = 0; i < files.size(); ++i)
              length += files.at(i).length;
      }
  }

  void TrackerClient::startSeeding()
  {
      firstSeeding = true;
      fetchPeerList();
  }

  void TrackerClient::stop()
  {
      lastTrackerRequest = true;
      fetchPeerList();
  }

  void TrackerClient::timerEvent(QTimerEvent *event)
  {
      if (event->timerId() == requestIntervalTimer) {
          fetchPeerList();
      } else {
          QObject::timerEvent(event);
      }
  }

  void TrackerClient::fetchPeerList()
  {
      QUrl url(metaInfo.announceUrl());

      // Base the query on announce url to include a passkey (if any)
      QUrlQuery query(url);

      // Percent encode the hash
      QByteArray infoHash = torrentDownloader->infoHash();
      QByteArray encodedSum;
      for (int i = 0; i < infoHash.size(); ++i) {
          encodedSum += '%';
          encodedSum += QByteArray::number(infoHash[i], 16).right(2).rightJustified(2, '0');
      }

      bool seeding = (torrentDownloader->state() == TorrentClient::Seeding);

      query.addQueryItem("info_hash", encodedSum);
      query.addQueryItem("peer_id", ConnectionManager::instance()->clientId());
      query.addQueryItem("port", QByteArray::number(TorrentServer::instance()->serverPort()));
      query.addQueryItem("compact", "1");
      query.addQueryItem("uploaded", QByteArray::number(torrentDownloader->uploadedBytes()));

      if (!firstSeeding) {
          query.addQueryItem("downloaded", "0");
          query.addQueryItem("left", "0");
      } else {
          query.addQueryItem("downloaded",
                             QByteArray::number(torrentDownloader->downloadedBytes()));
          int left = qMax<int>(0, metaInfo.totalSize() - torrentDownloader->downloadedBytes());
          query.addQueryItem("left", QByteArray::number(seeding ? 0 : left));
      }

      if (seeding && firstSeeding) {
          query.addQueryItem("event", "completed");
          firstSeeding = false;
      } else if (firstTrackerRequest) {
          firstTrackerRequest = false;
          query.addQueryItem("event", "started");
      } else if(lastTrackerRequest) {
          query.addQueryItem("event", "stopped");
      }

      if (!trackerId.isEmpty())
          query.addQueryItem("trackerid", trackerId);

      url.setQuery(query);

      QNetworkRequest req(url);
      if (!url.userName().isEmpty()) {
          uname = url.userName();
          pwd = url.password();
          connect(&http, SIGNAL(authenticationRequired(QNetworkReply*,QAuthenticator*)),
                  this, SLOT(provideAuthentication(QNetworkReply*,QAuthenticator*)));
      }
      http.get(req);
  }

  void TrackerClient::httpRequestDone(QNetworkReply *reply)
  {
      reply->deleteLater();
      if (lastTrackerRequest) {
          emit stopped();
          return;
      }

      if (reply->error() != QNetworkReply::NoError) {
          emit connectionError(reply->error());
          return;
      }

      QByteArray response = reply->readAll();
      reply->abort();

      BencodeParser parser;
      if (!parser.parse(response)) {
          qWarning("Error parsing bencode response from tracker: %s",
                   qPrintable(parser.errorString()));
          return;
      }

      QMap<QByteArray, QVariant> dict = parser.dictionary();

      if (dict.contains("failure reason")) {
          // no other items are present
          emit failure(QString::fromUtf8(dict.value("failure reason").toByteArray()));
          return;
      }

      if (dict.contains("warning message")) {
          // continue processing
          emit warning(QString::fromUtf8(dict.value("warning message").toByteArray()));
      }

      if (dict.contains("tracker id")) {
          // store it
          trackerId = dict.value("tracker id").toByteArray();
      }

      if (dict.contains("interval")) {
          // Mandatory item
          if (requestIntervalTimer != -1)
              killTimer(requestIntervalTimer);
          requestIntervalTimer = startTimer(dict.value("interval").toInt() * 1000);
      }

      if (dict.contains("peers")) {
          // store it
          peers.clear();
          QVariant peerEntry = dict.value("peers");
          if (peerEntry.type() == QVariant::List) {
              QList<QVariant> peerTmp = peerEntry.toList();
              for (int i = 0; i < peerTmp.size(); ++i) {
                  TorrentPeer tmp;
                  QMap<QByteArray, QVariant> peer = qvariant_cast<QMap<QByteArray, QVariant> >(peerTmp.at(i));
                  tmp.id = QString::fromUtf8(peer.value("peer id").toByteArray());
                  tmp.address.setAddress(QString::fromUtf8(peer.value("ip").toByteArray()));
                  tmp.port = peer.value("port").toInt();
                  peers << tmp;
              }
          } else {
              QByteArray peerTmp = peerEntry.toByteArray();
              for (int i = 0; i < peerTmp.size(); i += 6) {
                  TorrentPeer tmp;
                  uchar *data = (uchar *)peerTmp.constData() + i;
                  tmp.port = (int(data[4]) << 8) + data[5];
                  uint ipAddress = 0;
                  ipAddress += uint(data[0]) << 24;
                  ipAddress += uint(data[1]) << 16;
                  ipAddress += uint(data[2]) << 8;
                  ipAddress += uint(data[3]);
                  tmp.address.setAddress(ipAddress);
                  peers << tmp;
              }
          }
          emit peerListUpdated(peers);
      }
  }

  void TrackerClient::provideAuthentication(QNetworkReply *reply, QAuthenticator *auth)
  {
      Q_UNUSED(reply);
      auth->setUser(uname);
      auth->setPassword(pwd);
  }